1. Field of the Invention
The present invention relates to markers suitable for use in golf fairways, especially to indicate the distance of a particular position on the fairway to the green. The markers may also be used as distance markers for golf driving ranges, as markers for airport runways and taxiways or for soccer field corners, and as benchmarks in parks of public lands.
2. Prior Art
It is common for distance markers to be placed on golf fairways to help players estimate the distance of their ball to the green. Many of these markers are set flat into the ground and as such are hard to find.
Markers have also been used which project above the ground. However, such markers either have to be removed when the grass is being mowed, or have to be made very flexible so that they can be pushed flat by a mowing machine. The latter type of marker has two drawbacks. Firstly it is likely to become broken with repeated bending caused by frequent mowing operations. Secondly, it is not favoured by golfers since it interferes with the rolling of balls.
U.S. Pat. No. 5,219,171, which issued Jun. 15, 1993 to Kirby et al., proposes a golf fairway marker which collapses from a raised condition to a retracted, lowered condition when run over by a mowing machine. This includes a spring loaded central plunger and a series of trapezoidal leaves each having their narrower end held by the top of the plunger, and the wider end held by a surrounding support ring. This construction, in addition to being somewhat complex, has the drawback that the spring causes the plunger to rise as soon as the lead roller of a mower has passed over it, and so is subjected to repeated impacts by other parts of the mower.
U.S. Pat. No. 4,489,669, which issued Dec. 25, 1984 to Carman, shows a golf marker having a base and having an upper portion including a resilient dome which is depressed when a mower passes over it. There is nothing to delay recovery of the resilient dome to its normal position, so it would be expected that after a mower wheel or roller has run over it, the dome would spring back to its normal position where it could be cut by mower blades.